Arsenic is also found naturally in the enviornment - appleseeds for example will kill you if you digest enough.
So it would have to be an extreme natural situation.
Yes. So he ingested an unnaturally high concentration of dioxin at a Russian hosted dinner. These are the same Russians who openly and desperately wanted Yushchenko to lose.
I can think of no other conclusion to want happened than the obvious one. Neither can you.